Electromagnet.



No. 893,305. PATENTED JULY 14, 1908.

H. W. CHENEY. ELEGTROMAGNET.

APPLICATION FILED NOV.l4, 1907.

l I E i wwa Q MWXQ. 8%.. Wm @Xw UNITED STATES PATENT OFFICE.

HERBERT W. CHENEY, OF NORWOOD, OHIO, ASSIGNOR TO ALLIS-CHALMERS COMPANY, A

CORPORATION OF JERSEY, PANY, A CORPORATION OF OHIO.

AND THE BULLOCK ELECTRIC MANUFACTURING COM- ELECTROMAGNET.

Specification of Letters Patent.

Patented July 14, 1908.

I Original application filed June 8, 1906, Serial No. 320,767. Divided and. this application filed November 14, 1907.

Serial No. 402,103.

To all whom it may concern:

Be it known that I, HERBERT W. CHENEY, a citizen of the United States, residing at Norwood, in the county of Hamilton and State of Ohio, have invented certain new and useful Improvements in Electromagnets, of which the following is a full, clear, and exact specification.

My invention relates to the structure of electromagnets, particularly as applied to operating shortcircuiting devices in the manner set forth in my 00- ending applicatlon Serial No. 320,757, file June 8, 1906, of which this a lication is a division.

It is the 0 Ject of my invention to provide an electromagnet which shall be able to give certain results not hitherto obtained.

invention may be briefly described as conslsting of an 'electromagnet comprisin a winding and paramagnetlc arts movaile relatively to each other, eac of said parts having inserted in it a plug of higher magnetic retentivity to hold the relatively movable parts together after the winding has been denergized. Preferably one of said plugs is sprin mounted to take u the hammer-blow as t e parts come together and for other purposes.

' The various novel features of my invention will appear from the description and drawing and will be particularly pointed out in the claims.

The single figure of the drawing is a sect onal view of one embodiment of my invent1on.

The magnet shown is of the iron-clad solenold type and may be one of'a air of magnets for operatin any desired mechanism oppositely. The non frame 10 of the magnet is shown as extendin slightly to the right to receive the coil an form part of the companion magnet if there is one. From the lower part of the frame 10 a projection 11 projects upwardl within the coil 12, and at the inner end 0 this projection is a steel plunger 13, pressed upwardly by an adjustable spring 14. The inner surface of the projection 11 has a facing 15 of non-.magnetic material through which the plunger 13 extends. The core 16 of the magnet has embedded in its center a steel plug 17, which enlunger 13 gages with the spring-pressed he plunger when the magnet is energized.

13 and plug 17 serve a threefold purpose first, to take up the shock of the hammerblow when the core 16 reaches the end of its movement; second, by reason of higher retentivity of the parts 13 and 17, to retain the core 16, once it. has been attracted, in said attracted position after the coil 12 has been denergized, the magnet thushaving an electromagnetic actuating part and a permanently magnetic retaining art; and third, of special advantage when t e magnet is used. to operate a short-circuiting device, to allow the movement of such short-circuiting device to be completed when the magnet is energized, whatever the position of the motor shaft in its end-play, but after the magnet has been denergizedto return the actuating lever of said device to such a position that the sides of the groove of the short-circuiting device will not come into contact with the pin in said lever during the end-play of the shaft, the short-'circuiting device remaining fully closed or fully open as the case may be.

In the claims I aim to cover all such modi-' fications of the recise arrangement here shown andv descrl ed which may be made without departing from the spirit and scope of m invention.

W at I claim as new is 1. An electromagnet comprising a winding, and paramagnetic parts movable relatively to each other, each of said parts having inserted in it a plug of higher magnetic retentivity to hold the relatively movable parts together after the WlIldlIlg has been deenergized.

2. An. electromagnet COIIIPI'lSlIlg a wlnding, and paramagnetic parts n 1ovable relatively to each other, each of said parts having inserted in it a steel center to hold the relatively movable parts together after the winding has been denergized, one of sald steel centers being spring-mounted.

3. A solenoid electromagnet comprislng a winding, an iron frame extending partly within said winding, and a movable core, said inward extension and said core having steel centers to hold the core in attracted position after the magnet is denerglzed.

4. A solenoid electromagnet compnslng a winding, an iron frame extendlng partly within said winding, and 'a movable core, said inward extension and said core having plugs or higher magnetic retentivity to hold the core in attracted position after the magnet isjdeenergized, one of said plugs being spring-mounted.

5. A solenoid electromagnet comprisinga winding, an iron frame extendlng partly within said winding, a movable core, a plate of non=magnetic material betweensaid core and said inward extension, and plugs of higher magnetic retentivity insaid exten-' sion and said core respectively for holding the core in attracted position after the magnet is deenergized.

6. A solenoid electromagnet comprising a winding, an iron frame extending partly Within said winding, a movable core, a per forated plate of non-magnetic material between said core and said inward extension, and steel centers in said extension and said core res ectively for holding the core in attracte position after the magnet is deenergized, one of said steel centers being spring-mounted and one extending through said plate.

7. An electromagnet comprising a winding and paramagnetic arts movable relatively to each other, a p ate of non-magnetic material between said parts, and steel centers inserted in said relatively movable parts to hold them together after the winding has been deenergized, one of said steel-centers extendingrt hrough said plate.

8. An electromagnet comprising a winding and para magnetic arts movable relatively to each other, a p ate of non-magnetic material between said parts, and lugs of higher magnetic retentivity inserted in said relatively movable parts to hold them together after the winding has been denergiz'ed, one of said plugs extending through said plate and one of said plugs being spring-mounted.

In testimony whereof I aflix my signature, in the presence of two witnesses.

' HERBERT W. CHENEY.

Witnesses:

Gno. B. SoHLEY, FRED J. KJNSEY.. 

